The invention relates to shock absorbers in general, and more particularly to improvements in shock absorbers having a variable damping characteristic.
Commonly owned published German patent application No. 36 05 182 of Wessel discloses a shock absorber having a variable damping characteristic and being particularly suitable for use in motor vehicles. The shock absorber of Wessel comprises at least one fluid-containing cylinder or barrel for a piston which divides the internal space of the cylinder into two chambers and is connected with a piston rod which extends through and outwardly beyond one end wall of the cylinder. The piston-piston rod assembly of the shock absorber establishes one or more bypasses for the flow of fluid between the two chambers in response to penetration of a larger portion of the piston rod into or in response to extraction of a portion of the piston rod from the cylinder. The bypass or bypasses are controlled by solenoid valves.
Shock absorbers with bypasses for confined fluid are further disclosed in commonly owned U.S. Pat. No. 4,765,445 to Komossa et al. and in U.S. Pat. No. 4,726,453 to Obstfelder et al. Reference may also be had to commonly owned copending patent application Ser. No. 351,414 filed May 12, 1989 by Komossa and to commonly owned copending patent application Ser. No. 428,458 filed Oct. 30, 1989 by Neumann.